Joon-Soo (Jang Keun-Suk) is a rebellious high school kid, popular with the girls, but an absolute nightmare for his parents and teachers. Joon-Soo soon drives his parents batty enough that they decide to up and leave their house. When Joon-Soo finds out that his parents are AWOL he does what any party animal would do, he calls his friends over for a house party.

That afternoon, Joon-Soo prepares for the party by going to the grocery store and buying drinks & food . While at the grocery store, he briefly leaves his shopping cart unattended to check out the liquor selection. When he comes back to his shopping cart, he’s stunned to find a baby in his cart. Even more confounding, after waiting for hours at the store, nobody comes forward to claim the baby. And to top everything off, theres a note on the baby which claims Joon-soo is the father!

At first, Joon-Soo devises varies ways to abandon the child, but every time is spoiled by an unexpected event. When his teacher calls to warn him that he will be expelled if he misses another day, Joon-soo decides to bring the baby to school. This causes further scandal for Joon-Soo and eventually leads to his suspension. Through all this, Joon-Soo finds himself slowly becoming attached to the baby.